In the related art, an α-sulfofatty acid alkyl ester salt (α-SF salt) is widely used as a surfactant formulated with a powder detergent for clothes.
In the recent years, the α-SF salt has been manufactured as a group of particles (α-SF salt particle group) containing the α-SF salt at a high concentration, and by performing dry blending of the particle group and other detergent components, a powder detergent has been manufactured. Therefore, until being used by being blended with the detergent components after manufacturing, the α-SF salt particle group is transported or stored for a long period of time in some cases.
If the α-SF salt particle group is weighted down during transportation or stored in a high-temperature environment, unfortunately, the particles are aggregated with each other and solidified. Particularly, if the α-SF salt particle group contains a large amount of fine powder, the solidification more easily occurs.
Regarding the aforementioned problems, PTL 1 discloses that, by coating the α-SF salt particles with a coating agent and a liquid raw material, the solidification of the particle group containing the particles can be inhibited.